What it's used for
This medication is used to treat partial-onset seizures in patients 1 month of age and older, and as an add-on treatment for generalized tonic-clonic seizures in patients 4 years and older.
Source: U.S. FDA-approved prescribing information (openFDA).
Typical dosing
For adults, the starting dose is typically 50 mg to 100 mg twice daily, with a maximum recommended dose of 200 mg twice daily, while pediatric dosing is based on body weight.
Dosing shown here is the general FDA-labeled range. Your prescribing clinician determines the exact dose, form, and schedule for you — this is not a substitute for medical advice.
Common side effects
Common side effects and risks include dizziness, lack of coordination, fainting, and heart rhythm abnormalities.
Covered strengths on the Tab $0 list
Covered at $0 with an active Tab membership when filled at a participating pharmacy nationwide or through mail order. A licensed clinician must prescribe the medication.
Related medications
Other everything else medications covered at $0 with an active Tab membership.
Lacosamide dosage and administration
Adults (17 years and older): Initial dosage for monotherapy for the treatment of partial-onset seizures is 100 mg twice daily (2.1) Initial dosage for adjunctive therapy for the treatment of partial-onset seizures or primary generalized tonic-clonic seizures is 50 mg twice daily (2.1) Maximum recommended dosage for monotherapy and adjunctive therapy is 200 mg twice daily (2.1) Pediatric Patients 4 years to less than 17 years : The recommended dosage is based on body weight and is administered orally twice daily (2.1) Increase dosage based on clinical response and tolerability, no more frequently than once per week (2.1) Injection: for intravenous use only when oral administration is temporarily not feasible; the recommended dosage is based on body weight and is administered two or three times daily over 15 to 60 minutes;
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. Your prescribing clinician decides the exact dose, form and schedule for you — this is not medical advice.
Lacosamide side effects
The following serious adverse reactions are described below and elsewhere in the labeling: Suicidal Behavior and Ideation [see Warnings and Precautions (5.1)] Dizziness and Ataxia [see Warnings and Precautions (5.2)] Cardiac Rhythm and Conduction Abnormalities [see Warnings and Precautions (5.3)] Syncope [see Warnings and Precautions (5.4)] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity Reactions [see Warnings and Precautions (5.6)] Adjunctive therapy: Most common adverse reactions in adults (≥10% and greater than placebo) are diplopia, headache, dizziness, nausea, and somnolence (6.1) Monotherapy: Most common adverse reactions are similar to those seen in adjunctive therapy studies (6.1) Pediatric patients: Adverse reactions are similar to those seen in adult patients (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Somerset Therapeutics, LLC at 1- 800-417-9175 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. This is not a complete list. Report side effects to your clinician, and seek care for anything severe or unexpected.
Lacosamide drug interactions
7.1 Strong CYP3A4 or CYP2C9 Inhibitors Patients with renal or hepatic impairment who are taking strong inhibitors of CYP3A4 and CYP2C9 may have a significant increase in exposure to lacosamide. Dose reduction may be necessary in these patients. 7.2 Concomitant Medications that Affect Cardiac Conduction Lacosamide should be used with caution in patients on concomitant medications that affect cardiac conduction (sodium channel blockers, beta-blockers, calcium channel blockers, potassium channel blockers) including those that prolong PR interval (including sodium channel blocking AEDs), because of a risk of AV block, bradycardia, or ventricular tachyarrhythmia. In such patients, obtaining an ECG before beginning lacosamide, and after lacosamide is titrated to steady-state, is recommended.
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. Tell your clinician and pharmacist about every medication, supplement and over-the-counter product you take.
Common questions
Is lacosamide covered at $0 with Tab?
Yes. Lacosamide is on Tab's covered $0 generic list — every covered strength is $0 with an active membership, at participating pharmacies nationwide or by mail order.
Do I need insurance to get lacosamide through Tab?
No. Tab is a membership, not insurance. Covered medications are $0 with an active membership whether or not you have a health plan.
How do I get a lacosamide prescription with Tab?
Book a video visit with a licensed Tab clinician (unlimited visits are included with membership). If it's clinically appropriate, they send the prescription to your chosen participating pharmacy or by mail order.
What is the usual dose of lacosamide?
Adults (17 years and older): Initial dosage for monotherapy for the treatment of partial-onset seizures is 100 mg twice daily (2.1) Initial dosage for adjunctive therapy for the treatment of partial-onset seizures or primary generalized tonic-clonic seizures is 50 mg twice daily (2.1) Maximum recommended dosage for monotherapy and adjunctive therapy is 200 mg twice daily (2.1) Pediatric Patients 4 years to less than 17 years : The recommended dosage is based on body weight and is administered orally twice daily (2.1) Increase dosage based on clinical response and tolerability, no more frequently than once per week (2.1) Injection: for intravenous use only when oral administration is temporarily not feasible; (FDA-approved label, retrieved 2026-09-15. Your clinician sets your dose.)
What are the side effects of lacosamide?
The following serious adverse reactions are described below and elsewhere in the labeling: Suicidal Behavior and Ideation [see Warnings and Precautions (5.1)] Dizziness and Ataxia [see Warnings and Precautions (5.2)] Cardiac Rhythm and Conduction Abnormalities [see Warnings and Precautions (5.3)] Syncope [see Warnings and Precautions (5.4)] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity Reactions [see Warnings and Precautions (5.6)] Adjunctive therapy: Most common adverse reactions in adults (≥10% and greater than placebo) are diplopia, headache, dizziness, nausea, and somnolence (6.1) Monotherapy: Most common adverse reactions are similar to those seen in adjunctive therapy studies (6.1) Pediatric patients: Adverse reactions are similar to those seen in adult patients (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Somerset Therapeutics, LLC at 1- 800-417-9175 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. (FDA-approved label, retrieved 2026-09-15.)
What interacts with lacosamide?
7.1 Strong CYP3A4 or CYP2C9 Inhibitors Patients with renal or hepatic impairment who are taking strong inhibitors of CYP3A4 and CYP2C9 may have a significant increase in exposure to lacosamide. Dose reduction may be necessary in these patients. (FDA-approved label, retrieved 2026-09-15. Tell your clinician about every medication and supplement you take.)
Lacosamide is $0 on the covered list
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